<div *ngIf="chatModel===undefined">
  <nz-spin nzSimple></nz-spin>
</div>
<div *ngIf="chatModel!==undefined">
  <textarea nz-input
            [(ngModel)]="chatModel!.content"
            rows="10" cols="20"
            class="p-0 m-0 overflow-y-scroll">
  </textarea>
</div>
